Serum levels of androgens and estrogens and 'steroid-sensitive' liver proteins in early human pregnancy: influence on the gender of the offspring.

Serum androgens, estrogens, 'steroid-sensitive proteins', thyroid components, and albumin were measured twice within a 4-5 week interval in 44 cases of early normal pregnancy (gestational weeks 8-18). Positive correlations were found in the total material between dehydroepiandrosterone sulfate (DHAS) and testosterone (T), unconjugated and total estrone, albumin, tetraiodothyronine, and calculated free tetraiodothyronine concentrations and within 2-week intervals between DHAS and T, estradiol-17 beta, and unconjugated and total estrone, and between T and estradiol-17 beta and unconjugated estrone. Positive correlations were also found between the rates of change in DHAS of albumin. No significant association was found between 'steroid-sensitive proteins' and androgens or androgen/estrogen ratios. Women giving birth to girls had significantly higher serum levels of pregnancy-associated alpha 2-macroglobulin, thyroxine-binding globulin, and ceruloplasmin and lower ratios between T and sex hormone binding globulin than women giving birth to boys. The important role of placental aromatization in the metabolism of maternal androgens is well known. Albumin binding and thyroid status may also affect the metabolism of DHAS during pregnancy. The androgen/estrogen balance may be of little importance for the regulation of 'steroid-sensitive' proteins during early pregnancy. The mechanism behind the higher serum levels of pregnancy-associated alpha 2-macroglobulin, thyroxine-binding globulin, and ceruloplasmin in women giving birth to girls remains to be elucidated.